Vehicles having steering control by means of a handlebar, such as a motorcycle or scooter, typically have lever mechanisms pivotally mounted to the handlebar adjacent to the handlebar grips with a lever extending over and adjacent to the grip. These levers are typically used to pull cables or to activate hydraulic mechanisms that, in turn, activate the vehicle brake, throttle, or clutch. To utilize the lever mechanisms, the operator must loosen the grasp of the handlebar grip so as to extend the fingers outwardly and over the lever mechanism to grasp the lever portion with the thumb extended around the grip such that a squeezing motion may be used to activate the vehicle brake or clutch mechanism. The motion necessitates the operator to relinquish some control of the steering mechanism to accomplish the braking or clutch motion.
The majority of prior art handle controls, including thumb throttles, require activation by relinquishing some steering control to grip and squeeze an adjacent lever mechanism.
Various forms of twist grip mechanisms integrated into a handlebar operator grip have been proposed for activation of cable linked throttles wherein a twisting action of the handlebar grip draws a cable onto a rotatable pulley mechanism thereby pulling the cable to activate the throttle located at the remote end of the cable. These forms of twist throttle controls fix and route the control cable to the outside surface of the handlebar. These twist throttle mechanisms have a singular purpose of activating cable linked throttles; however, additional control functions such as clutch and brake control, in particular hydraulic systems, remain relegated to lever activation mechanisms.
Braking and clutch mechanisms, particularly on motorcycles, are often hydraulic thereby necessitating a hydraulic master cylinder to be mounted in close proximity to the operator's hand to accomplish the required activation leverage and hence are positioned on the outside of the handlebar near the operator grip. Hydraulic master cylinders incorporating a lever mechanism activation typically include the hydraulic lines that are lashed to outside surface of the handle bar resulting in exposure of the hydraulic system to damage and road debris as well as being unsightly from a design point of view.
What is needed is an improved handlebar mounted vehicle control grip device incorporating hydraulic brake or clutch control with a cable linked throttle control selectively activated by a twisting action of the grip, and having control cables and hydraulic lines positioned within the handlebar for protection and improved aesthetic appearance.